Seems to work amazingly although I'm a bit concerned about the security. A friend sent me $1. I get an email from square, link to website where I entered my debit #, expiry and postal. It deposited directly to my debit card (I didnt even know you could do that). The deposit already arrived! "Checking Card Adjustment POS Pin (Credit) $1.00" So I sent him $1 back (to: my friend, cc: cash@square.com, subject: $1). And i…
Another issue: if you make a mistake on the initial email, and want to send a different amount, you're out of luck. When you send a corrected email from the same address and go to the payment page, it adds any previously unfinished transactions from your email to the amount being sent, with no way to cancel the mistaken one. So just never make a mistake, and never do a test transaction you don't intend to finish, or you'll be required to finish and pay for all of it when you finally do have the correct amount and want to send a transaction (which you can only send with a small subset of the debit cards in existence).
These payment companies are always introducing interesting new things and then they hobble them with basic oversights and fundamentally flawed policies. In the last hour I've gone from excitement to disappointment with this service. It had promise based on the description, but this particular service (probably not Square itself) will fail very quickly.